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United States Patent | 5,162,194 |
Morgan | November 10, 1992 |
Method of providing a printed circuit board with a cover coat on a selected area thereof characterized by the steps of: i) applying a photoresist material to an area of the board not to be provided permanently with a cover coat; ii) applying a photosensitive material to both the photoresist and the area of the board to be provided with cover coat; iii) blanket exposing the board to light to promote reaction of photoresist material with photosensitive material only in areas in which the photosensitive material and photoresist interface; iv) removing the reaction product of photoresist material and photosensitive material from the interface areas; and v) curing the remaining photosensitive material to convert the cover coat.
Inventors: | Morgan; William M. (Chandlers Ford, GB) |
Assignee: | International Business Machines (Armonk, NY) |
Appl. No.: | 799721 |
Filed: | November 22, 1991 |
Oct 20, 1988[GB] | 8824542 |
Current U.S. Class: | 430/319; 430/311; 430/312 |
Intern'l Class: | G03C 011/12 |
Field of Search: | 430/311,312,319 |
4889790 | Dec., 1989 | Roos et al. | 430/319. |
Foreign Patent Documents | |||
58-122 | Jan., 1983 | JP. |
IBM Technical Disclosure Bulletin, vol. 19, No. 12, May 1977, p., 4539 by Abolafia et al, "Dual Density Mask For Photoresist". IBM (TDB) vol. 19, No. 12, May 1977, P. A. Hartley, Dual Density Mask for Photoresist (4540). IBM (TDB) vol. 22, No. 3, Aug. 1979, Hampson, R. A., Miller, E. D., Journal Take-Up Roll for Printer Mechanism. |